Distributed HVAC system cost optimization

Abstract

Various embodiments herein include at least one of systems, devices, methods, and methods for distributed HVAC system cost optimization. Such embodiments are generally implemented within a controller of HVAC system component, such as within boiler, cooler, air handling unit, and rooftop unit controllers. In some embodiments, multiple controllers exchange data to control various components of an HVAC system. One of the controllers, such as a primary plant of the system for heating or cooling, is designated as a master controller and the other component controllers are designated as slave controllers. Each controller, both master and slave controllers, includes at least one model that models variable settings of the component or components for which the respective controller is responsible. The model is utilized by the respective controller to both adjust the modeled variable component settings and to determine a cost-variable of operation.

What is claimed is: 
     
       1. A method comprising:
 storing, in a memory device of a Heating, Ventilation, and Air Conditioning (HVAC) plant controller designated as a master controller of an HVAC system including at least one other HVAC unit having a controller designated as a slave controller, variables of the HVAC plant that can be manipulated and within what limits and a model of costs and behavior of the HVAC plant with regard to the HVAC plant variables that can be manipulated; 
 identifying, through execution of instructions on at least one processor of the HVAC plant controller based on the HVAC plant model of costs and behavior stored in the memory device, a set of at least one variable movement and a cost benefit to the HVAC plant associated with the set; 
 transmitting, via a network interface device of the HVAC plant controller, data representative of the identified set to each slave controller; 
 receiving, from each of the slave controllers via the network interface device, at least data representative of a marginal cost difference associated with the identified set; 
 based on the identified cost benefit to the HVAC plant and the data received from each slave controller representative of the marginal cost difference associated with the identified set, determining whether the set would provide a cost benefit that at least meets a threshold parameter arid:
 when the set provides a cost benefit that at least meets the threshold parameter, implementing the set on the HVAC plant; and 
 when the set does not provide a cost benefit that at least meets the threshold parameter, restarting the method taking into account the set and other sets that do not provide a cost benefit that at least meet the threshold parameter; and 
 
 wherein:
 identifying the set and the cost benefit to the HVAC plant associated with the set includes identifying a plurality of sets of at least one variable movement and a respective cost benefit to the HVAC plant associated with the respective sets; 
 transmitting data representative of the identified set of at least one variable movement to each slave controller includes transmitting each of the plurality of sets; 
 receiving at least data representative of the marginal cost difference associated with the identified set includes receiving data representative of the marginal cost difference with regard to each of the sets; and 
 determining whether the set would provide a cost benefit that at least meets a threshold parameter includes:
 selecting a set from the plurality of sets of that provides a greatest cost benefit; and 
 for the selected set that provides the greatest cost benefit, determining whether the selected set would provide a cost benefit that at least meets the threshold parameter. 
 
 
 
     
     
       2. The method of  claim 1 , wherein implementing the set on the HVAC plant does not include transmitting any data commands to any of the slave controllers. 
     
     
       3. The method of  claim 1 , wherein identifying the set of at least one variable movement and a cost benefit to the HVAC plant associated with the set includes:
 choosing at least one incremental change to the at least one variables; 
 determining cost and behaviors to result from the chosen at least one incremental change; 
 when the determined behavior is to maintain a desired state of HVAC plant operation and the cost is a beneficial movement, identifying the at least one incremental change and its associated cost benefit as the set of at least one variable movement and associated cost benefit. 
 
     
     
       4. The method of  claim 1 , wherein the HVAC plant is a boiler and the at least one other HVAC unit is an air handling unit. 
     
     
       5. The method of  claim 1 , wherein the variables of the HVAC plant that can be manipulated include at least a temperature of supply fluid provided by the HVAC plant and a flow rate supply fluid provided by the HVAC plant. 
     
     
       6. The method of  claim 1 , wherein receiving at least data representative of the marginal cost difference associated with the identified set includes receiving data representative of infeasibility indicating that the identified set does not allow a respective slave controller to meet at least one constraint or setting of the HVAC system. 
     
     
       7. A Heating, Ventilation, and Air Conditioning HVAC plant controller comprising:
 at least one processor; 
 at least one network interface device; 
 at least one memory device storing:
 HVAC plant controller configuration data, the configuration data including:
 data designating the HVAC controller as a master controller of an HVAC system including at least one other HVAC unit having a controller designated as a slave controller; and 
 variables of an HVAC plant that the HVAC plant controller controls that can be manipulated and within what limits and a model of costs and behavior of the HVAC plant with regard to the HVAC plant variables that can be manipulated; 
 a control module including instructions executable by the at least one processor to:
 identify, based on the stored HVAC plant model of costs and behavior, a set of at least one variable movement and a cost benefit to the HVAC plant associated with the set; 
 transmit, via the network interface device, data representative of the identified set to each slave controller; 
 receive, from each of the slave controllers via the network interface device, at least data representative of a marginal cost difference associated with the identified set; 
 based on the identified cost benefit to the HVAC plant and the data received from each slave controller representative of the marginal cost difference associated with the identified set, determine whether the set would provide a cost benefit that at least meets a threshold parameter and implement the set on the HVAC plant when the set provides a cost benefit that at least meets the threshold parameter, otherwise, iterating execution of the control module taking into account the set and other sets that do not provide a cost benefit that at least meet the threshold parameter; and 
 wherein identifying the set of at least one variable movement and a cost benefit to the HVAC plant associated with the set includes: 
  choosing at leas one incremental change to the at least one variables; 
  determining cost and behaviors to result from the chosen at least one incremental change; and 
  when the determined behavior is to maintain a desired state of HVAC plant operation and the cost is a beneficial movement, identifying the at least one incremental chance and its associated cost benefit as the set of at least one variable movement and associated cost benefit. 
 
 
 
 
     
     
       8. The HVAC plant controller of  claim 7 , wherein implementing the set on the HVAC plant does not include transmitting any data commands to any of the slave controllers. 
     
     
       9. The HVAC plant controller of  claim 7 , wherein, in the control module:
 identifying the set and the cost benefit to the HVAC plant associated with the set includes identifying a plurality of sets of at least one variable movement and a respective cost benefit to the HVAC plant associated with the respective sets; 
 transmitting data representative of the identified set of at least one variable movement to each slave controller includes transmitting each of the plurality of sets; and 
 receiving at least data representative of the marginal cost difference associated with the identified set includes receiving data representative of the marginal cost difference with regard to each of the sets; and 
 determining whether the set would provide a cost benefit that at least meets a threshold parameter includes:
 selecting a set from the plurality of sets of that provides a greatest cost benefit; and 
 for the selected set that provides the greatest cost benefit, determining whether the selected set would provide a cost benefit that at least meets the threshold parameter. 
 
 
     
     
       10. The HVAC plant controller of  claim 7 , wherein the HVAC plant controlled by the HVAC plant controller is a cooling plant and the at least one other HVAC unit is an air handling unit. 
     
     
       11. The HVAC plant controller of  claim 7 , wherein, in the controller module, the variables of the HVAC plant that can be manipulated include at least a temperature of supply fluid provided by the HVAC plant and a flow rate supply fluid provided by the HVAC plant. 
     
     
       12. The HVAC plant controller of  claim 11 , wherein the supply fluid is cooled water-based fluid. 
     
     
       13. A non-transitory machine-readable medium, with instructions stored thereon, which when executed by at least one processor of a machine, cause the machine to:
 store, in a memory device of a Heating, Ventilation, and Air Conditioning (HVAC) plant controller, HVAC plant controller configuration data, the configuration data including:
 data designating the HVAC controller as a master controller of an HVAC system including at least one other HVAC unit having a controller designated as a slave controller; and 
 variables of an HVAC plant that the HVAC plant controller controls that can be manipulated and within what limits and a model of costs and behavior of the HVAC plant with regard to the HVAC plant variables that can be manipulated; 
 identify, based on the HVAC plant model of costs and behavior stored in the memory device, a set of at least one variable movement and a cost benefit to the HVAC plant associated with the set; transmit, via a network interface device of the HVAC plant controller, data representative of the identified set to each slave controller; 
 receive, from each of the slave controllers via the network interface device, a data representative of a marginal cost difference associated with the identified set; 
 based on the identified cost benefit to the HVAC plant and the data received from each slave controller representative of the marginal cost difference associated with the identified set, determine whether the set would provide a cost benefit that at least meets a threshold parameter and implement the set on the HVAC plant when the set provides a cost benefit that at least meets the threshold parameter, otherwise, iterating execution of the instructions taking into account the set and other sets that do not provide a cost benefit that at least meet the threshold parameter; and 
 wherein identifying the set of at least one variable movement and a cost benefit to the HVAC plant associated with the set includes:
 choosing at least one incremental change to the at least one variables: 
 determining cost and behaviors to result from the chosen at least one incremental change; 
 when the determined behavior is to maintain a desired state of HVAC plant operation and the cost is a beneficial movement, identifying the at least one incremental change and its associated cost benefit as the set of at least one variable movement and associated cost benefit. 
 
 
 
     
     
       14. The non-transitory machine-readable medium of  claim 13 , wherein implementing the set on the HVAC plant does not include transmitting any data commands to any of the slave controllers. 
     
     
       15. The non-transitory machine-readable medium of  claim 13 , wherein:
 identifying the set and the cost benefit to the HVAC plant associated with the set includes identifying a plurality of sets of at least one variable movement and a respective cost benefit to the HVAC plant associated with the respective sets; 
 transmitting data representative of the identified set of at least one variable movement to each slave controller includes transmitting each of the plurality of sets; and 
 receiving at least data representative of the marginal cost difference associated with the identified set includes receiving data representative of the marginal cost difference with regard to each of the sets; and 
 determining whether the set would provide a cost benefit that at least meets a threshold parameter includes:
 selecting a set from the plurality of sets of that provides a greatest cost benefit; and 
 for the selected set that provides the greatest cost benefit, determining whether the selected set would provide a cost benefit that at least meets the threshold parameter. 
 
 
     
     
       16. The non-transitory machine-readable medium of  claim 13 , wherein the HVAC plant controlled by the HVAC plant controller is a cooling plant and the at least one other HVAC unit is an air handling unit. 
     
     
       17. The non-transitory machine-readable medium of  claim 13 , wherein the variables of the HVAC plant that can be manipulated include at least a temperature of supply fluid provided by the HVAC plant and a flow rate supply fluid provided by the HVAC plant.